Wireless Bus Door Opener

Hello! I'm currently converting my van to a camper. The van was used as a passenger bus before, and has a passenger door in the back the flips open by activating a switch on the console. My plan is to install a wireless switch relay to be able to open the door from the outside with a fob. I found THIS or THIS that I think would get the job done. The problem is now that I don't know anything about the wires going from the door motor to the actual switch. All I can tell is that there are 2 red wires, 1 blue wire and then some brown or black ones going into the switch. Any ideas on how I can make that work? Thanks, Roland

Do you have a Digital Multi Meter? Can you pop out that switch panel and take a picture of the wires going to that switch? Controlling the door by making your connection(s) at the switch might be the easiest way to accomplish your goal. As far as the remote control system, does the van currently have remote keyless entry? You might be able to use a more common auto RKE system that would do more than just the side door.Soldering is fun!